1. Field of the Invention
The present invention relates generally to apparatus for filling grain drills with grain and, more particularly, to an air-powered or pneumatic apparatus for filling grain drills with grain.
2. Description of Relevant Art
Grain drills, devices for placing seeds or grain in the ground after a furrow or seedbed has been formed by a suitable tillage tool, are known in the art. Such drill apparatus often use a jet of air to deposit grain in the soil at the desired planting depth. A plurality of tubes carried by the grain drill may be arranged one after another with each tube operating to deposit a seed intermittently during travel of the drill. The grain drill typically includes a hopper or similar compartment in which is stored the supply of grain that is fed to the drill tubes. It is often necessary to fill and refill the grain drill hopper during a planting operation. For example, a farmer will stop at the end of a field near a gravity box or like device filled with grain, refill the grain drill, and then continue the planting operation.
Many prior art grain drills utilize an auger system to fill the hopper with grain. U.S. Pat. No. 2,746,621 discloses a seed box feeder for grain drills which includes a cover connected to the open upper end of the drill. At one end of the cover an inlet is provided through which grain is inserted. The grain is carried by an auger away from the inlet along the length of the seed box.
It also is known to position a tractor with a gravity box containing a large quantity of grain next to the grain drill, with an auger being used to carry grain from the box to the top of the grain drill. A second auger conveys the grain horizontally along the length of the inlet of the grain drill. The inlet of the grain drill has a length that may extend completely across from one side of the drill to the other. It is important that grain be delivered across the full length of the grain drill inlet in order to evenly distribute the grain among the seeding tools.
While prior art devices for filling grain drills perform satisfactorily, there remains room in the art for improvement with respect to apparatus for filling and refilling grain drills.